Fixing empty conduit on a floor slab with bitumen sheets?

First of all, hello everyone! As a new member and fresh builder in your forum, I now also have my first question for you and hope someone can help me......

I am currently working on laying the conduits for the electrical installation. Our house has no basement, so the floor slab was sealed with bitumen membranes. Now I am wondering how I can best attach the conduits for the electrical installation to the floor slab without damaging the bitumen membrane.....

Perhaps some of you have faced the same question before.....

Hello,

I am currently laying the cables on the bitumen sheets. I have bought screws with sealing washers on the washers (available at the hardware store) for this. Once all the cables are laid, I will fix the pipes with them and also apply a bit of silicone on each screw. That should then be watertight.

Hello alexo206, it’s been a while since the thread but I still want to give you an answer. (In case you build again ) We also drilled into the bitumen membrane... but in any case, you have to put a piece of bitumen back on each drill hole and simply go over it with the torch)